var year, years, i, j, numbers, letters;
[for (year of years) if (year > 2000) year];
year;
[for (i of numbers) for (j of letters) i+j];
[for (i of numbers) for (j of letters) if (i<j) i+j];

(for (year of years) if (year > 2000) year);
year;
(for (i of numbers) for (j of letters) i+j);
(for (i of numbers) for (j of letters) if (i<j) i+j);